Engine ignition timing arrangement

ABSTRACT

A primary embodiment of the invention employs a control assembly having a pressure responsive section and an electrically energizable section connected to each other and to the cooperating ignition distributor as by an arm pivotally connected to the distributor breaker plate; the pressure responsive section is connected so as to be responsive to engine intake vacuum, during certain predetermined conditions of engine operation, in order to advance the timing of the ignition spark while the electrically energizable section, comprised of a solenoid coil and armature, is operatively connected to electrical switch means also opened and closed to in accordance with preselected indicia of engine operation.

United States Patent [72] Inventor Raymond A. Soeters 1,992,383 2/1935 Mallory 123/1 17 Royal Oak. Mich. 3,162,184 12/1964 Walker 123/117 [211 Appl. No 780,127 3.301242 1/1967 Candelise 123/117 [22] Filed Nov. 29, 1968 FOREIGN PATENTS [45] Patented Feb. 9, 1971 Assignee Honey Carburetor Company 555,126 2/1960 Belgium 123/ 1 17 Warren, Mich. Primary ExaminerMark M. Newman a corporation of Michigan Assistant Examiner-Ronald B. Cap

At!rney-Walter Potoroka, Sr.

T [54] ENGiNE TIMING ARRANGEMEN ABSTRACT: A primary embodiment of the invention em- 5 Claims, 7 Drawing Figs.

ploys a control assembly having a pressure responsive section U.S. l7, and an electrically energizable ection onnected to ea h 92/99 other and to the cooperating ignition distributor as by an arm [5 Int. connected to the distributgr breaker late; the res. [50] Field Of Search 123/ l 17, ure responsive ection is connected so as to be responsive to engine intake vacuum, during certain predetermined conditions of engine operation, in order to advance the timing of the [56] References C'ted ignition spark while the electrically energizable section, com- UNITED STATES PATENTS prised of a solenoid coil and armature, is operatively con- 1,882,720 10/1932 Arthur 123/1 17 nected to electrical switch means also opened and closed to in 1,897,704 2/1933 Mallory 123/1 17 accordance with preselected indicia of engine operation.

PATENTED FEB 9|97l 3.561141 0 SHEET? 0F 3 INVENTOR. RAYMO/Vfl 4. 505

ATTORNEY 1 ENGINE IGNITION TIMING ARRANGEMENT BACKGROUND THE INVENTION Various ignition-timing control arrangements have been proposed by the prior art. Some of these have employed a single pressure responsive diaphragm for controlling the advance and retard of the ignition timing; others have employed two pressure responsive diaphragms,forming two pressure responsive chambers, each of which was placed in communication with two separate sources of vacuum.

However, such prior art devices have been found to be rather difficult in a calibration and tailoring to meet the specific requirements of aparticular engine design. This often results from the fact that, forexarnple, the dual diaphragm type of distributorcontrol, the indicia of engine operation as well as the motivating force for actuating the respective diaphragms is attained from twoseparate (but operationally related) sources of vacuum. Consequently, it becomes difficult, where required, to vary the operational characteristics of one of the diaphragms without producing some effect on the other diaphragm.

Further, the responsiveness of the prior art arrangements often has been relatively slow because movement of any of the diaphragms inboththe ignition advance and ignition retard direction required the accompanying flow of a considerable volumeofair.

SUMMARY OF THE INVENTION According to the primary invention, an engine ignition-timing control arrangement for advancing and retarding the timing of anassociated ignition distributor mounted in driven relationship to an internal combustion engine having an air induction passage controlled byv a variably p'ositioned throttle valve mounted therein comprises first pressure responsive means, second electrically responsive means, housing means containing said first pressure responsive means and said second electrically responsive means, said first means and said second means being operatively connected to said ignition distributor in order to effect both an advanceand a retard of the timing of saidignition distributor, said first pressure responsive means being effective when exposed to vacuum generated in accordance with indicia of engine operating conditions for advancing said timing of said ignition. distributor, and said second electrically re'sponsive'means being effective to retard said timing of said ignition distributor upon the occurrence of certain predetennined engine operating conditions.

Accordingly, a general object of this invention is to provide a control foran internal combustion'engine ignition-distributor which will have pressure responsive means for advancing the ignition timing of said ignition distributor and separately actuated electrically responsive means for retarding the ignition timing of said ignition-distributor.

Anotherobject of this invention is to provide a control as set forth above which will be responsive in its advance and re-' tard of said ignition timing to such conditions of engine opera- .tions as, for example, engine'idle operation, vehicle decelera tion, engine temperature and part-throttle engine operation.

Other more specific objects and advantages of the invention will become apparent when reference is made to the following detailed description when considered in conjunction with the accompanying drawings.

DESCRIPTION or THE DRAWINGS In the accompanying drawings: FIG. 1 illustratessin general axial cross section an ignitiontiming control arrangement, in association with an ignition distributor assembly (with portions thereof omitted for pur- FIG. 7 illustrates a further embodiment of the control structure of FIG. I and applicable for use in'any of the systems or arrangements disclosed by either of FIGS. 3, 4, 0r 6.

DESCRIPTION or PREFERRED EMBODIMENTS therewith. A breaker plate 24 mounted on a suitable bearing member, as'is well known in the art, is adapted to rotate, to a limited degree, about the driving shaft and cam 22. The

breaker plate 24 carries thereon a breaker arm assembly 26 which includes a cam engagingportion 28 to effect the make and break of the circuit of the contacts indicated at 30 and 32. The cam 22 and the shaft 20 on which it is mounted are, of course, rotated in timed relation with the engine by means of any transmission means well known in the art.

The air induction structure 14, having a body 34 with an induction passage 36 formed therethrough communicating at opposite ends with, for example, the atmosphere and the intake manifold passage 38, is provided with a throttle valve 40 secured to a transversely extending throttle shaft 42 soas to be capable of pivotal rotation within the induction passage 36. ln actualpractice the induction structure 14 may in fact be a carburetor and as such provided with a venturi 44 within passage 36 for purposes of metering fuel from an associated reservoir (not shown but well known in the art) to the air flowing through the induction passage and into the intake manifold conduit or passageway 38.

' Throttle shaft 42 may be rotatably positioned, as is well known in the art, by suitable control linkage means secured as to one end thereof. Throttle shafi 42 is also provided with an actuating member 46 secured to one end thereof in a manner so as to be rotatable with the throttle shaft. The upper or free end 48 of member 46 to adapted to engage an actuating plunger 50 of a switch assembly 52 and to close an electrical circuit through the switch assembly 52 whenever the throttle valve and shaft are rotated so as to place the throttle valve 40 in a nominally closed position as illustrated in FIG 1. Further, as also shown in FIG. 1, the body 34 has formed therein a conduit portion or port 54 which communicates between the induction passage 36 and suitable conduit means 37 leading to ,the spark timing control assembly 12. When the throttle valve 40 is in its nominally closed (idle) position, which may be fully.

closed in a carburetor of the type having an idle air bypass or I port 54 is placed in communication with the pressure up stream of throttle valve 40 which, in effect, may be substantially atmospheric pressure.

FIG. 2 illustrates, somewhat schematically, and in cross section, switch assembly 52 as being comprises of a suitable housing 56 containing a fixed electrical terminal contact 58 and a movable switch member 60 pivotally secured at 62 to a second terminal 64. Suitable resilient means such as a spring 66 normally urges switch member 60 in the circuit open position and against actuating plunger 50. The upper end 48 of lever or arm 46 may be provided with a transverse abutment portion 68 for engaging and releasing plunger 50 depending, of course, upon the movement of throttle shaft 42. It is, of course, to be understood that the construction of switch assembly 52 as herein disclosed is merely exemplary since many different switch assemblies, each ofwhich is well known in the art, could be employed to perform the desired function. namely, to open and close the related circuitry in accordance with the position or positions attained by throttle valve 40 and throttle shaft 42.

The spark timing control assembly 12 is illustrated as being comprised of housing sections 70, ,72 and 74 which, in assembled relationship, are secured, as by welding, to a support bracket assembly 76 in turn secured to distributor housing 18 as by screws 78 and 80.

A solenoid coil assembly 82, fixedly secured within housing 74 generally slidably receives a movable core or armature 84, centrally thereof. One end of armature 84 has formed therein a generally medially disposed slot 86 for the relatively loose reception therein of a tongue portion 88, pivotally secured therein as by a transversely extending pivot pin 90, of a control arm 92 having its other end pivotally connected as to 94 to the rotatable breaker plate 24.

Bracket 76 also supports thereon, in electrically insulated relationship thereto, an electrical terminal assembly 96 connected at one end to electrical conductor 98, leading to terminal or fixed contact 58, and at its other end to a conductor 100 leading to solenoid winding or coil 82. The coil 82 is also provided with a second electrical lead or conductor 102 which may be ground as through the distributor housing 18 as generally indicated at 104.

An annular support member 106, of preferably magnetically permeable material is suitably retained as at its outer peripheral edge by housing section'74 so as to be fixedly retained therein as against an internally formed shoulder 108. The inner aperture of member 106 relatively tightly engages the outer diameter of a sleevelike tubular bushing 1 which is preferably formed of brass. Bushing 110 as well as bearing or bushing support member 106 are retained in the positions shown while, of course, annature or core 84 within bearing 110 is axially movable with respect thereto.

Housing sections 70 and 72 cooperate with each other to peripherally retain therebetween, as by flange portions 112 and 114, a flexible or pressure responsive diaphragm 116 which defines at opposite sides thereof two variable but distinct chambers 118 and 120. Chamber 118 is in constant communication with conduit 37 while chamber 120 may be vented directly to the atmosphere as by suitable ports or apertures indicated typically at 122. Accordingly, it can be seen that, generally, housing sections 70, 72 and diaphragm 116 cooperate to define a pressure responsive motor assembly and that such motor assembly is in turn fixedly secured, through any suitable fastening, joining or securing means, to housing section 74.

A washerlike abutment or stop member 124 is secured to one side of diaphragm 116 while a spring plate or perch 126 is secured to the opposite side of diaphragm 116. Oppositely disposed members 124 and 126 may be retained as by a hollow rivetlike fastener 128 peened at its opposite ends against such members 124 and 126. As can be seen, the interior of fastener 128 slidably accommodates therethrough an extension 130 of core 84 which carries, secured thereto, an annular spring perch or abutment 132 serving to axially contain a compression spring 134 between the abutment 132 and diaphragm plate member 126. Normally, spring 134 tends to cause relative motion as between, for example, abutment plate or member 124 and core extension 130 and in this way normally maintain the core 84 and plate 124 in axial abutting engagement as through the end of fastener 128.

A cup shaped caplike member 136, located generally within chamber 1 18, has a radiating flange 138 with a circular groove formed therein for receiving a seal 140. A second compression spring 142 engaging, at one end, housing section 70 and the flange 138 of cap 136 urges the cap 136 into sealing engagement with diaphragm plate 126. The sealing effect is, of course, provided by seal 140 so as to prevent pressure leakage as from chamber 120 to chamber 118 via the sliding tolerances as between core extension 130, rivet or fastener 128 and associated elements. Spring 142 also serves to urge diaphragm 116 and its associated plate members to the right, as viewed in FIG. 1, to a point whereat abutment plate 124 abuts against an abutment surface 144 which may be of annular configuration and formed by housing section 74.

OPERATION As is generally well known in the art, internal combustion engines of the reciprocating piston type, require, in order to attain optimum operating efficiencies, a degree of regulation in the timing of the ignition spark with respect to the angle of rotation of the crankshaft. Such regulation is usually referred to as either advancing or retarding the spark with the terms advance (or advancing) and retard" (or retarding) being employed with regard to the instant of ignition spark occurrence with reference to a predetermined angular position of the crankshaft as well as the direction of change in such timing as when, for example, the ignition spark timing is at a maximum advance position but is being changed slightly to a lesser advanced position. This interim movement or change could be referred to as retarding" the spark and as such the term of reference is in the sense of the direction of change of timing.

Further, as is also well known in the art, a maximum manifold vacuum is generated when the throttle valve is in its closed position and the vehicle is decelerating and simultaneously driving the engine. Another indicium of engine operation can be sensed by the high manifold vacuum (less than at deceleration) generated by the engine during idle engine operation at which time, of course, the throttle valve is closed, which means closed to the engine idle position. Such manifold vacuums will of course exist below or posterior to the closed throttle valve and generally, such manifold vacuums will decrease in value.(so as to have the pressure thereof more nearly approach atmospheric pressure) as the throttle valve is rotated from its closed position toward a position of wideopen throttle.

Referring now specifically to the construction of FIG. 1 it can be seen that with the engine assumed to be at idle operation and throttle valve 40 closed the port 54 leading to conduit means 37 is prevented from exposure to the manifold vacuum below throttle valve 40 but is exposed to the substantially atmospheric pressure within induction passage 36 anterior or upstream of the throttle valve 40. Consequently, both chambers 118 and 120 of spark timing control assembly 12 are at substantially identical pressure thereby permitting spring 142 to hold the diaphragm 116 and abutment or stop plate 124 in the position shown. Accordingly, it can be seen that spark or ignition advance is achieved by virtue of the manifold vacuum generated by the engine only when the throttle valve 40 begins to open.

However, as is also shown in FIG. 1, when the throttle valve 40 is closed lever or actuating member 46 closes switch member 60 against contact 58 thereby completing a circuit from a source 146 of electric potential (grounded as at 148) via a conductor 150 and through conductors 98 and to solenoid winding or coil 82 and through conductor 102, to, again, ground at 104. Solenoid coil 82 is thusly energized causing core or armature 84 to move to the right, due to the air gap 151, until it abut against metallic stop member 154, which is disposed within the end 152 of the casing for the coil 82, thereby creating a predetermined degree of spark retard in the ignition timing by causing control arm 92 to rotate the distributor breaker plate 24, and breaker arm assembly 26 situated thereon, a predetermined distance clockwise as viewed in FIG. 1. The U-shaped stop 154 is disposed centrally within the member 152, and it is formed with a radial slot 153 to accommodate the free reception therethrough of said control arm 92.

It should be apparent, in view of the above, that during vehicle deceleration with the throttle valve 40 closed, the identical results would be obtained with regard to ignition timing as achieved during engine idle operation.

When the throttle valve is rotated from its closed position to some other part throttle position, as shown for example at 400, port 54 becomes exposed to the engine or manifold vacuum posterior to the throttle valve and such vacuum is communicated via conduit means 37 to chamber 118 of housing section 70. Since chamber is at atmospheric pressure, a pressure differential is thereby created across diaphragm 116 causing the diaphragm 116, abutment plate 124, diaphragm plate 126, and cap or housing 136 to move to the left against the resilient resistance of spring 142. In so moving, spring 134 causes solenoid armature 84'to-also move to the left carrying control arm 92 with it so as to rotate-breaker plate 24 and breaker arm assembly 26 counterclockwise resulting in advancing the ignition timing. The degree of spark advance will of course depend on the calibrated force of spring 134 and the magnitude of the vacuum'generated by the engine which, in turn, is also controlled by the position of the throttle valve both of which reflectengine load.

SECOND EMBODIMENT FIG. 3 illustrates another embodiment of the invention; all elements of FIG. 3 which are like or similar to those of the elements of FIG. 1 are identified with like reference numbers.

In the embodiment of FIG. 3, a pressure responsive electrical switch assembly 160 is provided to at times complete or break the circuit leading to the solenoid'coil 82 of ignition control 12. Switch assembly 160 is illustrated as being comprised of housing sections 162, 164 which cooperate to peripherally retain therebetween a pressure responsive wall or diaphragm member 166 which serves to generally define two variable but distinct chambers 168,170 the first of which may be vented to the atmosphere as by means of suitable apertures formed through the housing section 162 as typically illustrated at 172. Housing section 164 may be provided with atubular extension, suitably secured within the wall of the engine intake manifold 16, with a conduit 174 formed therethrough so as to place chamber 170 in continual communication with the induction passage or interior 38 of intake manifold 16.

Chamber 168, generally, contains a. fixed contact terminal 176 connected as by a conductor 178 to terminal post'96 of the ignition spark control assembly 12. A movable switch member 180 pivotally secured to a second electrical terminal 182, connected to source 146- via conductor 189, is normally biased toward engagement with fixed contact 176 as by means of a compression spring 184 situated between switch member 180 and housing section 162. A switch member actuator 186 secured to diaphragm 166, for movement'therewith, is urged upwardly, by a spring 188 contained within chamber 170, so

as to engage and move switch member 180 upwardly out of engagement with contact 176 in order to open the circuit therethrough. g

As can be seen, the operation of the advance mechanism of the control 12 is the same asdescribed with reference to FIG. 1. However, the operation of the retard mechanism of the control 12 is achieved through the opening and closing of the switch assembly 160. That is, when a predetermined value of manifold vacuum is attained a pressure differential is attained across diaphragm 166 causing the diaphragm and actuator 186 carried thereby. to move downwardly, against the resistance of spring 188, so as to permit spring 184 to seat movable switch member 180 against fixed contact 176. When this happens, solenoid coil 82 is, of course, energized causing armature 84 to. move to the right rotating breaker plate 24 clockwise and retarding the ignition spark timing at discussed with reference to FIG. 1. As stated before, the manifold vacuum at which switch member 180 will be closed is a predetermined'value selected in order to be indicative of a particular attained engine operating condition. If this selected value were, for example, the, value of manifold vacuum at idle rump EMBODIMENT FIG. 4 illustrates a third embodiment of the invention. All elements in FIG. 4 which are like or similar to the elements of either FIGS. 1, 2 or 3 are identified with like reference numbers.

' In comparing the embodiments of FIGS. 1, 3 and 4 it can be seen that the embodiment of FIG. 4 appears to be, generally, a

' combination of the embodiments of FIGS. 1 and 3 with the extion control 12 of FIG. 4 is, as can be seen, like that of the vacuum advance portion of either FIGS. 1 or 3. That is, engine generated vacuum is communicated to port 54, conduit means 37 and chamber 1 18 only upon movement of the throttle valve 40 a distance sufficient to plate port- 54 in communication with the pressure in the induction passage 36 on the engine side of the throttle valve 40.

' In the embodiment of FIG. 4, it can be seen that when a predetermined value of manifold or engine vacuum is created, the pressure differential across diaphragm 166 causes actuator 186 to be moved downwardly, against the resistance of spring 188, thereby enabling spring 18410 move switch member 180 away from contact 176 and opening the electrical circuit between conductors 190 and 178.

Accordingly, it'can be appreciated that if the force of spring 188 were such as to maintain switch member 180 closed for all vacuum values of manifold vacuum less than or equivalent to idle engine operation, the only time that the core 84.would move to its retard position would be at idle engine operation because: (1) during normal driving conditions throttle valve 40 will be in some partly opened positioned causing the electrical circuit through switch assembly 52 to be opened; and (2) during vehicle deceleration with the throttle valve 40 closed and the vehicle driving the engine the valve of the manifold vacuum will .exceed the value of manifold vacuum generated at idle engine operation causing diaphragm 166 to move downwardly opening the electrical circuit through switch assembly a.

FOURTH EMBODIMENT FlG. 5 illustrates another embodiment of the invention; all elements of FIG. 5 which are like or similar to the elements of either FIGS. 1, 2, 3 or 4 are identified with like reference numbers.

In the embodiment of FIG. 5 a temperature sensing electrical switch assembly 200 is situated so as to have a suitable temperature responsive element or means 202 within the coolant 204 of the engine coolant system, fragmentary illustrated at 206. Switch assembly 200 may be further comprised of a housing 208 within which are situated a fixed contact terminal 210 and a cooperating movable switch member 212 pivotally secured to a second terminal 214. Fixed contact terminal 210 is electrically connected to post terminal 96 via conductor 216 while terminal 214 is connected to fixed contact terminal 58 (see FIG. 2) by means of a conductor 218. A compression spring 220 may be employed normally maintain the electrical circuit through switch assembly 200 closed by urging switch member 212 toward engagement with fixed contact 210. A suitable motion transmitting member or means 222 is provided in order to cause upward movement of switch member 212, thereby opening the circuit through switch assembly 200, whenever the temperature of the coolant 204 has attained a predetermined temperature.

As in FIG. 4, it can be seen that in the embodiment of FIG. 5 the electrical actuating circuitry includes switch assemblies 52 and 200 in series with each other. Accordingly, both switch assemblies 52 and 200 must be closed in order to attain energization of the coil assembly 82 and thereby actuate core or armature 84 to effect to retard of ignition timing. If either the throttle valve 40 is moved toward an open position, as at 400,

or the temperature of the coolant exceeds a predetermined temperature the circuit to solenoid coil 82 is opened and no retard of ignition timing via armature 84 can be achieved. This particular feature becomes very important in especially truck engine applications where engine temperature may increase because of heavy engine loads. In such instances a retard of the ignition timing could well increase such engine temperature above that considered acceptable for continued operation.

Fifth Embodiment FIG. 6 illustrates what may be considered to be a further modification of any of the systems disclosed by FIGS. 1, 3, 4 and 5 as well as that of FIG. 7 yet to be described. All elements of HO. 6 which are like or similar to those of either FIGS. 1, 2, 3, 4 or 5 are identified with like reference numbers.

Basically, the modification resides in the provision of a remotely situated power switch assembly 224, for completing or opening the power circuitry comprised of conductors 226 and 228, and the employment of switch assembly 52 (which may be physically situated on the carburetor 14) as a control switch thereby requiring control conductors 230 and 232 (respectively connected to terminals 58 and 64 of switch assembly 52) to carry only a relatively low current and low voltage so as to minimize any possible incident of switch arcing as between movable contact 60 and fixed contact 58. Of course, the arrangement would be one where, for example, closure of switch assembly 52 would cause the switch assembly 224 to complete the circuit to solenoid coil 82 through conductors 226 and 228.

Sixth Embodiment FIG. 7 illustrates another embodiment of the invention; all elements in FIG. 7 which are like those elements of FIGS. 1 and 2 are identified with like reference numbers.

In the embodiment of FIG. 7, the ignition spark timing control assembly 12a also defines an electrical retard mechanism and a vacuum or pressure responsive advance section as does the structure specifically disclosed in FIG. 1.

1n the arrangement of FIG. 7, the spark timing control assembly 12a is illustrated as being comprised of housing sections 370, 372 and 374 which, in assembled relationship, are secured, as by welding, to a support bracket assembly 376 which is in turn secured to the distributor housing 18 as by means of screws 78 and 80.

A solenoid coil assembly 382, fixedly secured within housing 374 generally slidably receives a movable core or armature 384, centrally thereof. One end of armature 38 i is provided with a reduced portion 386 for receiving thereabout a bracketlike tab 388 of a control arm 392 having its other end pivotally connected as at 394 to the rotatable breaker plate 24. Bracket 376 may carry an insulating grommet 396 for admitting therethrough conductor 98 leading from fixed contact 58, of switch assembly 52, to solenoid coil 382. Coil or winding 382 may also be provided with a second electrical lead or conductor 402 which may be connected to and grounded through the distributor housing 18 as generally indicated at 104.

Housing sections 370 and 372 cooperate with each other to peripherally retain therebetween, as by flange portions 412 and 414, a flexible or pressure responsive diaphragm 416 which defines, at opposite sides thereof, two variable but distinct chambers 418 and 420. Chamber 418 is in constant communication with conduit means 37 while chamber 420 may be vented directly to the atmosphere as by suitable ports or apertures indicated typically at 422. Accordingly, it can be seen that, generally, housing sections 370, 372 and diaphragm 416 cooperate to define a pressure responsive motor assembly and that such motor assembly is in turn fixedly secured, through any suitable fastening, joining or securing means, to housing section 374.

Oppositely disposed diaphragm reinforcing members 424 and 426 may be retained as by a suitable fastener or rivet 428. Reinforcing'or plate member 424 is adapted to have one end of a spring 442, contained within chamber 418, seated thereagainst while reinforcing member 426 may take the form of a cup-shaped cage, with a radially inwardly directed flange portion 441, for retaining therein a compression spring 434 continually urging the armature or core 384 to the left by engaging an enlarged head portion 431 thereof.

In view of the above it can be seen that, due to the air gap 381, whenever the electrical circuit leading to solenoid coil or winding 382 is closed, armature or core 384 will move to the right against the resistance of compression spring 434 thereby causing control lever or arm 392 .to rotate the breaker plate 24 clockwise as to retard the ignition spark timing. The degree of spark retard will be determined by .the distance available for movement as exists between the surface 454 on armature head 431 and cooperating end abutment surface 456 provided by housing section 374. When sufficient vacuum is admitted to chamber 418, diaphragm 416 responds by moving to the left against spring 442, carrying cage 426 and armature 384 with it. Since armature 384 is connected to control arm 392 the breaker plate 24 will be rotated counterclockwise advancing the ignition spark timing. The degree of ignition advance will, of course, depend on the degree or magnitude of the vacuum communicated to chamber 418 with the maximum advance being susceptible of determination by a threaded portion 450, formed on or carried by armature 384, and a cooperating threaded stop nut member 452 threadably adjustable therealong.

In view of the preceding it can be seen that the various embodiments and/or modifications of the invention provide a novel ignition distributor timing control which employs a pressure responsive motor section and an electrically energizeable section for effecting an advance and retard in the ignition spark timing. The respective sections are made respectively responsive to preselected indicia of engine operation so that optimum engine operating efficiencies are achieved regardless of the then conditions of engine operation.

The various linkages, levers and switches herein disclosed have been, for purposes of clarity, illustrated somewhat schematically. it will be readily apparent, especially to those skilled in the art, that the invention can be practiced employing, for example, switch assemblies of a multitude of differing configurations without the necessity of inventive faculties. Further, it should be apparent that the practice of the invention does not require, specifically, a lever or arm as disclosed at 46 and that a switch-actuating member may in fact be operatively connected to the throttle-actuating linkage but located physically remote with respect to the throttle shaft and carburetor structure. it is also contemplated that suchan actuating member may, in fact, take the form of a suitable camlike member having provision for adjustment so as to vary its effectiveness with respect to the angular position of the throttle valve. Further, it is possible, if desired, to provide, in the switch assemblies, typically shown at 52, variable electrical resistance means engageable by, for example, a movable wiper contact effectively positioned by the lever or arm 46 to vary the current flow to the solenoid coil assembly in accordance with the position of the throttle valve.

Although only a select numberof embodiments and modifications of the invention have been disclosed and described, it is apparent that other embodiments and modifications of the invention are possible within the scope of the appended claims.

I claim:

1. An engine ignition-timing control arrangement for advancing and retarding the timing of an associated ignition distributor mounted in driven relationship to an internal combustion engine having an air induction passage controlled by a variably positioned throttle valve mounted therein, said timing arrangement comprising first pressure responsive means; second electrically responsive means; housing means containing said first pressure responsive means and said second electrically responsive means; said first means and said second means being opcratively connected to said ignition distributor in order to effect both an advance and a retard of the timing of said ignition distributor; said first pressure responsive means being effective when exposed to vacuum generated in accordance with indicia of engine operating conditions for advancing said timing of said ignition distributor; said second electrically responsive means being effective to retard said timing of said ignition distributor upon the occurrence of certain predetermined engine operating conditions; said air induction passage comprising a carburetor, including a passageway formed in a wall of said carburetor so as to be in communication with said air induction passage and located so as to be in communication with said air induction passage at a point anterior to said throttle valve when said throttle valveis in its closed position, including conduit means communicating between said passageway and said first pressure responsive means within said housing means; said electrically responsive means comprising a solenoid coil, an armature movable with respect to said coil upon electrical energization of said coil, circuit means electrically interconnecting said solenoid coil to a source of electrical energy, first electrical switch means serially connectedin said circuit means, second electrical switch means serially connected in said circuit means; said first and second switch means being collectively effective to close said circuit means whenever said first and second switch means are both in a closed condition in order to electrically energize said solenoid coil and thereby cause said armature to retard said timing of said ignition distributor; said first switch means being effectively closed upon the occurrence of a first predetermined indicium of engine operation; said second switch means being effectively opened upon the occurrence of a second predetermined indicium of engine operation; a condition of closed throttle engine operation comprising said first predetermined indicium of engine operation; and the attainment of a preselected value of engine temperature comprising said second predetermined indicium of engine operation.

2. An engine ignition-timing control arrangement for advancing and retarding the timing of an associated ignition distributor mounted in driven relationship to an internal combustion engine having an air induction passage controlled by a variably positioned throttle valve mounted therein, said timing arrangement comprising first pressure responsive means; second electrically responsive means; housing means containing said first pressure responsive means and said second electn'cally responsive means; said first means and said second means being operatively connected to said ignition distributor in order to effect both an advance and a retard of the timing of said ignition distributor; said first pressure responsive means being effective when exposed to vacuum generated in accordance with indicia of engine operating conditions for advancing said timing of said ignition distributor; said second electrically responsive means being effective to retard said timing of said ignition distributor upon the occurrence of certain predetermined engine operating condition; said housing means comprising at least a first housing section and a second housing section; said first pressure responsive means comprising a pressure responsive diaphragm peripherally retained in sealing relationship between said first and second housing sections; said first housing section and said diaphragm cooperating to define a first general chamber thcrebetween; said second housing section and said diaphragm cooperating to generally define a second chamber; said second electrically responsive means comprising a solenoid assembly carried within said second chamber; said solenoid means comprising a solenoid coil fixedly situated within said second chamber and an armature slidably received within said coil and movable with respect thereto and said second housing section, including first abutment means for limiting the movement of said armature upon energization of said coil; first spring means for urging said diaphragm in a direction toward said second chamber; resilient motion transmitting means interconnecting said diaphragm and armature so as to cause said diaphragm and said armature to move in unison with each other when vacuum of sufficient magnitude is admitted to said first chamber; and linkage means for opcratively connecting said armature to said ignition distributor; said resilient motion transmitting means being effective to permit relative motion between said diaphragm and said armature upon electrical energization of said solenoid coil.

3. An engine ignition-timing control arrangement according the claim 1 including adjustable abutment means for positively limiting the maximum distance to which said diaphragm can move in the direction of said first chamber.

4. An engine ignition-timing control arrangement according to claim 1 wherein said solenoid armature includes an enlarged head end; and said resilient motion transmitting means comprises a cage portion carried by said diaphragm within said second chamber, said cage portion being formed as to generally loosely receive said head end therein, second spring means situated within and carried by said cage normally biasing said armature head end in the direction of said diaphragm; and abutment means carried by said armature for determining the maximum distance to which said diaphragm can move in the direction of said first chamber.

5. An engine ignition-timing control arrangement according to claim 1 wherein said solenoid armature includes a portion extending through said diaphragm in sliding relationship thereto; and said resilient motion-transmitting means comprises second spring means operatively connected to a free end of said armature portion and said-diaphragm so as to normally resiliently urge said free end and said diaphragm in directions away from each other, and including second abutment means effective for determining the maximum distance to which said first spring means can move said diaphragm in the direction of said second chamber. 

1. An engine ignition-timing control arrangement for advancing and retarding the timing of an associated ignition distributor mounted in driven relationship to an internal combustion engine having an air induction passage controlled by a variably positioned throttle valve mounted therein, said timing arrangement comprising first pressure responsive means; second electrically responsive means; housing means containing said first pressure responsive means and said second electrically responsive means; said first means and said second means being operatively connected to said ignition distributor in order to effect both an advance and a retard of the timing of said ignition distributor; said first pressure responsive means being effective when exposed to vacuum generated in accordance with indicia of engine operating conditions for advancing said timing of said ignition distributor; said second electrically responsive means being effective to retard said timing of said ignition distributor upon the occurrence of certain predetermined engine operating conditions; said air induction passage comprising a carburetor, including a passageway formed in a wall of said carburetor so as to be in communication with said air induction passage and located so as to be in communication with said air induction passage at a point anterior to said throttle valve when said throttle valve is in its closed position, including conduit means communicating between said passageway and said first pressure responsive means within said housing means; said electrically responsive means comprising a solenoid coil, an armature movable with respect to said coil upon electrical energization of said coil, circuit means electrically interconnecting said solenoid coil to a source of electrical energy, first electrical switch means serially connected in said circuit means, second electrical switch means serially connected in said circuit means; said first and second switch means being collectively effective to close said circuit means whenever said first and second switch means are both in a closed condition in order to electrically energize said solenoid coil and thereby cause said armature to retard said timing of said ignition distributor; said first switch means being effectively closed upon the occurrence of a first predetermined indicium of engine operation; said second switch means being effectively opened upon the occurrence of a second predetermined indicIum of engine operation; a condition of closed throttle engine operation comprising said first predetermined indicium of engine operation; and the attainment of a preselected value of engine temperature comprising said second predetermined indicium of engine operation.
 2. An engine ignition-timing control arrangement for advancing and retarding the timing of an associated ignition distributor mounted in driven relationship to an internal combustion engine having an air induction passage controlled by a variably positioned throttle valve mounted therein, said timing arrangement comprising first pressure responsive means; second electrically responsive means; housing means containing said first pressure responsive means and said second electrically responsive means; said first means and said second means being operatively connected to said ignition distributor in order to effect both an advance and a retard of the timing of said ignition distributor; said first pressure responsive means being effective when exposed to vacuum generated in accordance with indicia of engine operating conditions for advancing said timing of said ignition distributor; said second electrically responsive means being effective to retard said timing of said ignition distributor upon the occurrence of certain predetermined engine operating condition; said housing means comprising at least a first housing section and a second housing section; said first pressure responsive means comprising a pressure responsive diaphragm peripherally retained in sealing relationship between said first and second housing sections; said first housing section and said diaphragm cooperating to define a first general chamber therebetween; said second housing section and said diaphragm cooperating to generally define a second chamber; said second electrically responsive means comprising a solenoid assembly carried within said second chamber; said solenoid means comprising a solenoid coil fixedly situated within said second chamber and an armature slidably received within said coil and movable with respect thereto and said second housing section, including first abutment means for limiting the movement of said armature upon energization of said coil; first spring means for urging said diaphragm in a direction toward said second chamber; resilient motion transmitting means interconnecting said diaphragm and armature so as to cause said diaphragm and said armature to move in unison with each other when vacuum of sufficient magnitude is admitted to said first chamber; and linkage means for operatively connecting said armature to said ignition distributor; said resilient motion transmitting means being effective to permit relative motion between said diaphragm and said armature upon electrical energization of said solenoid coil.
 3. An engine ignition-timing control arrangement according the claim 1 including adjustable abutment means for positively limiting the maximum distance to which said diaphragm can move in the direction of said first chamber.
 4. An engine ignition-timing control arrangement according to claim 1 wherein said solenoid armature includes an enlarged head end; and said resilient motion transmitting means comprises a cage portion carried by said diaphragm within said second chamber, said cage portion being formed as to generally loosely receive said head end therein, second spring means situated within and carried by said cage normally biasing said armature head end in the direction of said diaphragm; and abutment means carried by said armature for determining the maximum distance to which said diaphragm can move in the direction of said first chamber.
 5. An engine ignition-timing control arrangement according to claim 1 wherein said solenoid armature includes a portion extending through said diaphragm in sliding relationship thereto; and said resilient motion-transmitting means comprises second spring means operatively connected to a free end of said armature portion and said diaphragm so as to normaLly resiliently urge said free end and said diaphragm in directions away from each other, and including second abutment means effective for determining the maximum distance to which said first spring means can move said diaphragm in the direction of said second chamber. 